Clutch arrangement in an automatic transmission having an installation space-saving coolant supply

ABSTRACT

A clutch arrangement in an automatic transmission, comprising two axially adjacent multi-disk clutches (B, E) to each is assigned a piston/cylinder arrangement for axially actuating the clutch, a pressure compensation space for a dynamic clutch actuation pressure compensation and a mechanism for supplying lubricant or cooling medium. The aim is to reduce the axial overall length of a transmission of this type. The disk packets of both clutches (B, E) are placed one above the other in a radial manner, the pressure compensation space ( 25 ) for the radially outer clutch (B) is permitted to axially border on the pressure space ( 8 ) for actuating the piston ( 17 ) of the radially inner clutch (E), and the lubricant or cooling medium flow ( 30 ) for the radially outer clutch (B) is directly tapped from the pressure compensation space ( 25 ) for actuating the outer clutch (B).

According to the preamble of claim 1, the invention relates to a clutcharrangement in an automatic transmission having space-saving coolantsupply.

Multiple examples exist for the arrangement of clutches and actuatingdevices thereof in automatic transmissions. U.S. Pat. No. 6,120,410shows a clutch arrangement in an automatic transmission in which a part,designed somewhat cup-shaped in transverse section, is constructed as anouter disc carrier. Radially within the outer disc carrier are formedthe inner and outer discs of two multi-disc clutches disposed axiallyadjacent on the same radial height, piston-cylinder arrangements havingeach one actuating piston for actuation of the two clutches, the same aspressure compensation spaces for a dynamic pressure compensationregarding the actuating force of the actuating pistons.

Also known from this publication is to form a pressure compensationspace using one clutch piston and one so-called baffle plate, the sameas to situate one recoil spring between the baffle plate and the piston.Lubricant is supplied to the pressure compensation space via a lubricanthole of the outer disc carrier.

Further known from the Applicant's unpublished DE-102 48 172 is anautomatic transmission having a multi-disc clutch which has one servedevice located within a disc carrier in the form of a piston-cylinderarrangement with dynamic pressure compensation for actuating a clutch.In addition, a planetary gearset, having one planet carrier, belongs tothis automatic transmission.

The servo device of this transmission consists of one piston which,together with a suitably designed wall of the disc carrier, forms apressure space. A pressurization of the pressure space, via apressure-medium supply hole in the disc carrier, produces an axialdisplacement of the piston toward the discs after overcoming the recoilforce of a spring.

Upon the side of the piston opposite the pressure space, a pressurecompensation space is situated by way of a dynamic pressure appearingupon the clutch as a result of the clutch rotation is compensated atleast approximately. To this end, the pressure compensation space isfilled with a lubricant fed via a hole placed in a hub of the disccarrier. In this known transmission, at the same time, the pressurecompensation space, located radially below the clutch discs, is formedby one streamlined spacer disc as an axially stationary baffle plate andby a cup-shaped section of the axially displaceable actuating piston.

Lubricant is supplied to the planetary gears and to the pressurecompensation space, via a common lubricant supply situated in the areaof the inner diameter of the streamlined spacer disc, and is fed by thealready mentioned lubricant supply hole. On the radially inner lubricantinlet in the pressure compensation chamber, the lubricant flow from thelubricant supply hole is divided in two partial flows where one partialflow is guided to the pressure compensation chamber and a second partialflow is guided to a lubricant chamber near the planetary gears.

To obtain the shortest clutch arrangement length, this transmissionprovides for a streamlined spacer disc, which has axially, stampedcorrugations of radial direction distributed over its periphery. Theaxially-formed, stamped grooves are connected either with a lubricantchamber for lubricating the planetary gears or with the pressurecompensation space for the clutch actuating pistons.

Against this background, the invention is based on the problem ofintroducing a clutch arrangement for an automatic transmission which,with great saving of space, makes possible the supply with a lubricantor coolant of at least one pressure compensation space and of at leastone multi-disc clutch possible.

The solution of this problem results form the features of the main claimwhile advantageous developments and other embodiments can be deducedfrom the sub-claims.

According to DE-102 48 172, the invention is based on the knowledge thata division of the lubricant and/or coolant flow is not necessary andthat at least one clutch allows for at least one clutch actuating pistonwith the lubricant and/or coolant feeding from the pressure compensationchamber.

The point of departure of the invention is, therefore, a clutcharrangement for an automatic transmission having two axially adjacent,multi-disc clutches B, E with each of which are coordinated onepiston-cylinder arrangement for the axial clutch actuation; one pressurecompensation space for a dynamic clutch actuating pressure compensation,and means for lubricant or coolant supply. According to the invention,this transmission provides for disc sets of both clutches B, E to beradially placed one above the other; the piston-cylinder arrangementsfor actuation of both clutches B, E to be disposed at least to a greatextent axially adjacent; the pressure compensation space for theradially outer clutch B abuts axially on the pressure space foractuating the piston of the radially inner clutch E, and that thelubricant or coolant flow for the radially outer clutch B to be tappablefrom the pressure compensation space for actuating the outer clutch B.

In one development of the invention, a disc carrier is provided betweenthe pressure space for actuating the piston of the radially inner clutchE and the pressure compensation space for the piston of the radiallyouter clutch B, which is situated on which the inner discs of the outerclutch B and the outer discs of the inner clutch E are jointly fastenednon-rotatably and axially movably.

In this connection, it is advantageous that this common disc carrier beconnected by its radially inner section with a hub located upon atransmission shaft.

In addition, it is preferred that an actuating cylinder be situated uponthe hub in the cup-shaped aperture of which a radially inner section ofthe piston for actuating the outer clutch B is axially movably passedforming a pressure space.

In another development of the invention, the actuating cylinder can bealso designed with two parts; the radially inner wall being implementedby the outer side of the hub and the axial rear wall and radial outerwall by one part mounted on the hub and axially secured by a guard ring.

To reduce the assembly cost, it can also be provided that a sealingelement can also be provided to vulcanize the inner side of the axiallyaligned section of the pressure cylinder.

According to the invention, to minimize the axial length of theautomatic transmission, it is additionally proposed that the sidepointing away axially from the pressure space of the piston-cylinderarrangement for the radially outer clutch B and the radially innersection of the common disc carrier form the pressure compensation spacefor the actuating piston for the radially outer clutch B.

To ensure a recoil motion of the actuating piston for the outer clutch Bwhen the actuating pressure relaxes, it is additionally proposed that inthe pressure compensation space, coordinated with the above mentionedactuating piston, one recoil element be located which directly orindirectly supports itself by one of its ends on the actuating pistonand by its other end on a radially inner section of the common disccarrier.

In another very important development of the invention, now with morespace saving, it is now proposed that in the pressure compensation spacean essentially radially aligned, baffle plate be fastened on the axiallyinner section of the common disc carrier so that between the two partsthere is formed a coolant or lubricant guide space leading to the outerclutch B in order to be able to transport the coolant or lubricant fromthe pressure compensation space for the actuating piston of the radiallyouter clutch B to the latter.

The baffle plate is preferably designed so as to have, in a radiallyinner section, a passage through which the coolant or lubricant canenter from the pressure compensation space for the outer clutch B intothe coolant or lubricant guide room.

For relaying the coolant or lubricant, it is preferred that, in the areaof radially outer section of the baffle plate in the common disccarrier, a radial aperture be formed through which the coolant orlubricant can pass.

In a further development of the invention, radially above the aperturein the common disc carrier, between the disc carrier and a radiallyouter section of the actuating piston for the radially inner clutch E,one duct is formed for the coolant or lubricant flow, which ultimatelyleads to the common disc carrier for both clutches E, B.

To make guiding the coolant or lubricant flow possible from the innerside of the common disc carrier to the clutch discs, it can also beprovided that in a paraxially aligned section of the common disccarrier, radially aligned apertures are formed through which the coolantor lubricant flow is guided directly to the discs of the outer clutch B.

Another positive aspect of the invention concerns the axial arrangementof the pistons relative to the common disc carrier. In the radial areaof the inner clutch E, it is preferably provided that both actuatingpistons be disposed axially directly on the right and left sidesadjacent the common disc carrier.

It is a further advantage that on its radially inner section, the baffleplate is pressed by the recoil element situated in the pressurecompensation space against the radially inner section of the common disccarrier so as to ensure or at least support the axial press fit of thisbaffle plate on the common disc carrier.

For assembly reasons, on its radially outer section, it is preferredthat the baffle plate be effectively clamped, radially on the inner sideof a horizontally aligned section of the common disc carrier.

The baffle plate can also carry a sealing means on the inner side of itsradially outer section, which pressure-tight seals the pressurecompensation space against the actuating piston for actuation of theouter clutch B. The sealing means can be, for example, vulcanized on thebaffle plate, but can also be made as a separate structural element.

In development of the inventive clutch arrangement, with regard to thepressure space of the piston-cylinder arrangement for actuating theradially inner clutch E, it is proposed that it be essentially formed bythe wall of the inner section of the common disc carrier pointing awayfrom the pressure compensation space for the actuating piston of theouter clutch B and by a radially inner section of the actuating pistonfor the radially inner clutch E.

To implement a dynamic pressure compensation for the actuating pistonfor the radially inner clutch, in addition, it is preferable to providethat, upon the side pointing away from the pressure space of theactuating piston for the inner clutch E, a pressure compensation spaceis formed, which is axially limited by a baffle plate fastened on thehub, the same as radially by the hub an by the “t” leg of the piston onthe left side and pointing away from the common disc carrier.

To make possible a recoil motion of the actuating piston for theradially inner clutch E in the pressure compensation space for theactuating piston, a recoil element is situated which supports itselfaxially by one end on the baffle plate and by the other end on theactuating piston.

It is most advantageous in this design that the baffle plate seals thepressure compensation space against the left side “t” leg of the pistonby a sealing agent.

It is also appropriate that the piston for the actuation of the innerclutch E be axially passed by its right-side “t” leg to an essentiallyhorizontally aligned sector of the common disc carrier.

As to the fastening of the baffle plate and of the cup-shaped housing ofthe piston-cylinder arrangement for the radially outer clutch B, it canalso be provided that the parts be held axially upon the hub by means ofsnap rings or guard rings.

The hub itself is located upon an axial continuation of the transmissionhousing and supported against it via an axial bearing.

The transmission shaft upon which the hub carrying the common disccarrier is situated is preferably designed as transmission input shaft.

In one other development of the inventive clutch arrangement, it isprovided that upon the side of the baffle plate remote from the pressurecompensation space for the actuating piston of the inner clutch E, aninner disc carrier of the inner clutch E is situated and connected witha transmission shaft.

It is further advantageous that between the inner disc carrier of theinner clutch E, a flow duct is formed for receiving a lubricant orcoolant flow for the inner clutch E.

For reasons of installation space, it is adequate that on the sideremote from the last mentioned flow duct of the inner disc carrier ofthe radially inner clutch E, the outer disc carrier of the radiallyouter clutch B is placed.

Another development of the invention provides that the outer disccarrier of the radially outer clutch B is situated on a transmissionshaft which, via an axial bearing, is secured against the transmissionshaft upon which is fastened the inner disc carrier of the inner clutchE.

It is also advantageous that the transmission shaft, upon which theinner disc carrier of the inner clutch E is fastened, is supportedagainst the hub by means of an axial bearing.

Another embodiment of the invention only marginally related to thespace-saving clutch arrangement, but nevertheless very advantageous isto be seen in the actuating piston of the outer clutch B, is designed onits radially outermost end as rotational speed indicator for arotational speed sensor which is passed through the transmission housinginto the spatial proximity of the rotational speed indicator.

Furthermore, the radial arrangement of the discharge aperture in thebaffle plate defines the maximum level of fluid that the lubricant torcoolant taps in the pressure compensation space for the actuating pistonof the outer clutch B.

The coolant and lubricant are applied to the pressure compensation spacefor the piston of the outer clutch B and to the clutch at least instages via a hole in the hub.

The pressure compensation space for the actuating piston of the radiallyinternally situated clutch is, on the contrary, supplied with coolant orlubricant via a hole in the hub which, for its part, is inflowconnection with a hole in one of the transmission shafts.

Finally, the pressure space for the piston-cylinder arrangement foractuation of the outer clutch B is supplied with an actuating pressuremedium via a hole in the hub which, for its part, is connected accordingto inflow technique with a hole or peripheral groove in the continuationof the transmission housing.

Lastly, let it be known that the pressure space of the actuatingcylinder for the radially inner clutch E is also filled, via a hole inthe hub, which is inflow connection, via a separate hole or annulargroove, in the continuation of the transmission housing.

One drawing is enclosed with the description to clarify the inventiveclutch arrangement, the same as other advantageous embodiments anddevelopments of the invention. The drawing shows a cross-section throughan automatic transmission in the area of two multi-disc clutches E and Blocated in a transmission housing 2 directly adjacent each other bothradially and axially.

The basic concept of this clutch arrangement provides that the clutch Eis situated radially within a clutch space formed by a disc carrier ofthe clutch B. The disc carrier is designated with 9 and designed as acommon disc carrier for both clutches B, E on which an inner disc 22 ofa disc set of the radially outer clutch B and an outer discs 24 of adisc set of the radially inner clutch E are disposed axially movably andnon-rotatably. The disc set of the (inner) clutch E is, therefore,situated on a smaller diameter than the disc set of the (outer) clutchB, spatially seen, preferably radially below the disc set of the (outer)clutch B. The common disc carrier 9 is preferably installed in the areaof the side close to the transmission housing of the clutches E, B.

It is further provided that an outer disc carrier 38 of the outer clutchB and an inner disc carrier 37 of the inner clutch E is situated on theside of the clutches E, B remote from the transmission housing and isnon-rotatably connected with transmission shafts 39 or 40.

On the common disc carrier 9 are axially stationarily fastened on enddiscs 13, 15 serving for the discs of both clutches B, E as supportagainst actuating forces exerted upon the discs by clutch actuatingdevices. The stability thereof is ensured by a snap ring 16 clamped in astop groove on the common disc carrier.

On the side of the clutch discs, axially opposite the snap ring 16,there is axially movably disposed on each one of the two clutches B, E,upon the common disc carrier 9, one compression ring 32, 33 againstwhich can be exerted an actuating force by way of a clutch actuatingdevices for closing the clutches 35. The closing force acts in bothclutches E, B in the same direction. The pressure rings 32, 33 can eachbe designed, for example, as a corrugated spring.

Both clutch actuating devices involved are designed as piston-cylinderarrangements integrated in the transmission. In the embodiment shownhere, a pressure-space 6 forming actuating cylinder of the actuatingarrangement for the radially outer clutch B is designed with two partshaving one cylinder 5 and one hub 3. The cylinder 6 is designed, forexample, as a metal plate converting part or as a cast metal part in theform of a pot open in direction of the disc set of the clutch B with oneradially and one axially aligned section. The cylinder 5 is here mountedon the hub 3 on the inner diameter of its radially aligned section andsecured by means of a guard ring 4 against an axial displacement indirection to a transmission housing 2. By way of this design, theradially outwardly pointing side of the hub 3 forms the second part ofthe pressure-space 6 forming an actuating cylinder of the actuatingarrangement for the radially outer clutch B. The cylinder 5 is herepressure-tight sealed against the hub 3. In the embodiment shown, asealing element 67 is to this end vulcanized on the inner side of theaxially aligned section of the cylinder 5. But in another development,it can also be provided that the cylinder 5 is sealed, relative to thehub 3, by a separate sealant inserted in a suitable groove or recess ofthe cylinder or of the hub 3. Such a separate sealant can be, forexample, a commercially available O-ring or a shaped seal.

The hub 3 is coaxially aligned to the two clutches B, E and rests on anaxial continuation 52 of the housing 2; is rotatably supported on thecontinuation 52 and is axially propped by means of an axial bearing 52against the continuation 52. In this connection, it also is to beobserved that a radially outwardly extending section 54 is formed on thehub 3, which is part of the common disc carrier 9 or at leastoperatively connected therewith.

Reverting to the actuating device for the radially outer clutch B, it isto be observed that thereto belongs an actuating piston 10 which isaxially movably lodged in the cylinder 5 forming the pressure space 6.The piston 10 is passed near the transmission housing 2 to the radiallyouter clutch B and brought to abut on the pressure ring 32 thereof.Besides, on a radially outermost end 65 of the actuating piston 10, aperipheral delimitation is formed which serves as rotational speedsignal indicator for a rotational speed sensor 12 introduced through thetransmission housing 2.

On the side of the actuating piston 10 remote form the pressure space 6,a pressure compensation chamber 25 for the piston 10 is formed, otherwall parts being formed by the hub 3 or by a radial section 54 thereof.

One recoil element 26 is located paraxially aligned to the actuationdirection 35 and designed here in this pressure compensation space 2,for example, as a compression spring set. Instead of the compressionspring set, a plate spring obviously can also be used. The recoilelement 26 is prestressed between the central section 54 of the commondisc carrier 9 and the piston 10. In the embodiment shown, a disc-shapedsection of a baffle plate 34 is clamped between the end of thecompression spring set (26) on the disc carrier side and the section 54of the disc carrier whereby the baffle plate 34 is axially pressed onthe disc carrier 9. In another development, the recoil element 26 canobviously abut directly axially on the section 54 of the disc carrier inwhich case another suitable axial security has to be provided for thebaffle plate 34.

The baffle plate 34 for its part is clamped between the radial section54 of the hub 3 and a paraxial section 47 of the common disc carrier 9in a manner such that in the area of the section 47, it rests on aparaxial section 50 of the actuating piston 10.

It is to be mentioned in this connection that between the actuatingpiston 10 and the cylinder 5 or the hub 3, the same as between thepiston 10 and the baffle plate 34, sealants 41, 46, 49 are situated bymeans of which the pressure space 6 and the pressure compensation space25 are axially movably sealed against each other and againstnon-pressurized transmission areas.

The pressure space 6 for the piston-cylinder arrangement 3, 5, 10 foractuating the outer clutch B is supplied with an actuating pressuremedium via a hole 58 in the hub 3 which for its part is connected byinflow technique with a hole or peripheral groove 27 in the continuation52 of the transmission housing 2.

The pressure compensation space 25 is filled with a lubricant and/orcoolant via a hole 57 in the hub 3 which is fed by a hole or peripheralgroove 29 in the continuation 52 of the transmission housing 2.

Regarding the filling of a pressure space 8 for actuating the innerclutch E, it is provided that the filling be effected via a hole 66 inthe hub 3 which is inflow connection with a separate hole or an annulargroove 28 in the continuation 52 of the transmission housing 2.

The baffle plate 34 is now designed and introduced in the pressurecompensation space 25 so as to keep a flow duct 59 free between thelatter and the radial section 54 of the hub 3 which, leading to thepressure compensation space 25, has one inlet aperture 51 for thecoolant or lubricant and one outlet aperture 48 in the horizontalsection 47 of the common disc carrier 9.

The place of the inlet aperture 51 in the flow duct 59 is selected inradial direction to the baffle plate 34 so as to coincide with apredetermined overflow height 7 in the pressure compensation space 25.

Coolant or lubricant reaching the duct 59 from the pressure compensationspace 25 migrates radially outwardly during operation of thetransmission as result of centrifugal forces so that it passes thisaperture 48 in the horizontal section 47 of the common disc carrier 9and, according to the dotted line, moves farther radially outwards intoa flow duct 62 between the common disc carrier 9 for both clutches B, Eand an actuating piston 17 for the inner clutch E. This liquidsubsequently reaches via piercing 14 in a paraxial section 63 of thecommon disc carrier 9 which bears the clutch discs between the clutchdiscs of the outer clutch B.

As this illustration makes clear, the proposed design veryadvantageously and with axial saving of installation space effects thesupply of the outer clutch B with coolant or lubricant, the pressurecompensation space 25 being able, at the same time, to serve as astorage space for the coolant or lubricant medium.

The actuating device for the radial inner clutch E is formed by apiston-cylinder arrangement, the pressure space 8 of which is delimitedby a paraxial section of the hub 3, the side pointing away from thebaffle plate 34 of the radial section 54 of the hub 3 and one section ofthe actuating piston 17 of this actuating device.

The actuating piston 17 for actuating the radially clutch E has anapproximately “t” shaped, across-sectional geometry with a radiallyinner section, a radially outer section, the same as a left-side “t” leg42 pointing to the common disc carrier 9. The ride-side “t” leg 43pointing to the common disc carrier 9 is here passed to the paraxialsection 47 of the common disc carrier 9.

The pressure space 8 is, in addition, sealed against the hub 3 via asealing medium 44 between the common disc carrier 9 and the right-side“t” leg 43 of the actuating piston 17, the same as via a sealing medium60 on the radially innermost section of the actuating piston 17.

On the side of the actuating piston 17, opposite the pressure space 8 ofthe actuating device for the inner clutch E, a pressure compensationspace 31 is formed for the latter. Via a hole 61 in the hub 3, the sameas a hole here (not shown in the transmission shaft 1), coolant orlubricant is supplied.

In this pressure compensation space 31 can also be seen a recoil element18, here designed as plate spring, which supports itself axially by oneside on the actuating piston 17 and by the other side on a baffle plate19. The baffle plate 19 is mounted on the hub 3 and axially secured bymeans of a snap ring 36.

On its radial end, the baffle plate 19 in addition carries a sealant 45by means of which the pressure compensation space 31 is sealed againstthe piston 17.

Upon the side of the baffle plate 19 remote from the pressurecompensation space 31 (shown in dotted line) is a flow route 64 for acoolant or a lubricant flow 20 which, from the area of the hub 3, leadsradially outwardly to the inner side of the inner disc carrier 37 forthe inner clutch E. By way of piercing in the inner disc carrier 37, thefluid reaches directly between the discs of the clutch E. The coolant orlubricant flow 20 is fed via one hole in a transmission shaft.

Finally, for the sake of completion of the description of this clutcharrangement, let it be known that the inner disc carrier 37 carrying adisc 23 of the inner clutch E is connected with the transmission shaft39 which, in this embodiment, supports itself via an axial bearing 55against the hub 3 and the transmission shaft 1.

The same is provided for the outer disc carrier 38 of the radially outerclutch B which carries outer discs 21 on a paraxial section 11. Saidouter disc carrier 38 is connected with another transmission shaft 40and/or other transmission parts (not shown here), and is axiallysupported by means of an axial bearing 56 against the just mentionedtransmission shaft 39.

REFERENCE NUMERALS

-   1 transmission shaft; transmission input shaft-   2 transmission housing; cover of the transmission housing-   3 hub-   4 guard ring-   5 cylinder for the actuating device for the radially outer clutch B-   6 pressure space for clutch B-   7 overflow height in the pressure compensation space for clutch B-   8 pressure space for clutch E-   9 common disc carrier for clutches B and E-   10 actuating clutch for clutch B-   11 paraxial section on the disc carrier for the outer discs of the    clutch B-   12 rotational speed sensor-   13 end disc of the clutch B-   14 piercing for lubricant oil supply of clutch B-   15 end disc of the clutch E-   16 snap ring-   17 actuating piston of the clutch E-   18 recoil element for the piston of the clutch E-   19 baffle plate of the clutch E-   20 coolant flow for clutch E-   21 outer discs of the clutch B-   22 inner discs of the clutch B-   23 inner discs of the clutch E-   24 outer discs of the clutch E-   25 pressure compensation space for the clutch B-   26 recoil element for the clutch B-   27 hole or peripheral groove in the continuation 52-   28 hole or peripheral groove in the continuation 52-   29 hole or peripheral groove in the continuation 52-   30 coolant or lubricant flow for the clutch B-   31 pressure compensation space for the clutch E-   32 compression ring for clutch B-   33 compression ring for clutch E-   34 baffle plate in the pressure compensation space for clutch B-   35 closing direction of the clutches B and E-   36 snap ring-   37 inner disc carrier of the inner clutch E-   38 outer disc carrier for the outer clutch B-   39 transmission shaft-   40 transmission shaft-   41 sealant-   42 left “t” leg of the actuating piston 17-   43 right “t” leg of the actuating piston 17-   44 sealant-   45 sealant-   46 sealant-   47 paraxial section of the common disc carrier 9-   48 aperture in the common disc carrier-   49 sealant-   50 paraxial section of the actuating piston 10-   51 aperture in the baffle plate 34-   42 axial continuation of the transmission housing-   53 axial bearing-   54 central section of the common disc carrier 9 or radial section of    the hub 3-   55 axial bearing-   56 axial bearing-   57 hole in the hub 3 for supply of the pressure compensation space 5-   58 hole in the hub 3 for supply of the pressure space 6-   59 coolant or lubricant guide space for the coolant or lubricant    flow 30-   60 sealant-   61 hole for supply of the pressure compensation space 31-   62 flow duct for the coolant or lubricant flow 30-   63 paraxially aligned outer section of the common disc carrier 9-   64 flow route-   65 radially outer section of the piston 10-   66 hole in the hub-   67 sealant

1-38. (canceled)
 39. A clutch arrangement in an automatic transmissioncomprising two axially adjacent multi-disc clutches (B, E) to each ofwhich is assigned a piston-cylinder arrangement for axial clutchactuation, a pressure space for axial actuation, a pressure compensationspace for a dynamic clutch actuation pressure compensation and means forlubricant or coolant supply, the two clutches (B, E) are disposedradially one above another, piston-cylinder arrangements for actuationof the two clutches (B, E) are at least to a great extent axiallydisposed side by side, a pressure compensation space (25) for a radiallyouter clutch (B) is located axially next to a pressure space (8) foractuation of a piston (17) of a radially inner clutch (E) and alubricant or coolant (30) for the radially outer clutch (B) can bedirectly tapped from the pressure compensation space (25) for actuationof the outer clutch (B).
 40. The clutch arrangement according to claim39, wherein between the pressure space (8) for actuation of the piston(17) of the radially inner clutch (E) and the pressure compensationspace (25) for a piston (10) of the radially outer clutch (B), a commondisc carrier (9) of the radially inner and of the radially outer clutch(B, E) is situated on which both inner discs (22) of the outer clutch(B) and also outer discs (24) of the inner clutch (E) are jointlynon-rotatably and axially movably fastened.
 41. The clutch arrangementaccording to claim 40, wherein the common disc carrier (9) is connectedon a radially inner section with a hub (3) of the disc carrier (9)situated upon a transmission shaft (1) and connected with thetransmission shaft (1).
 42. The clutch arrangement according to claim39, wherein upon a hub (3), one cylinder (5) is situated in a cup-shapedaperture of which and forming a pressure space (6), a radially innersection of a piston (10) for the outer clutch (B) is axially movablypassed.
 43. The clutch arrangement according to claim 42, wherein thecylinder (5) is formed in two parts, a radially inner wall thereof beingformed by an outer side of the hub (3) and a axially rear wall andradially outer wall by one part mounted on the hub (3) and secured bymeans of a guard ring (4).
 44. The clutch arrangement according to claim42, wherein the cylinder (5) is sealed tight against a pressure mediumrelative to the hub (3).
 45. The clutch arrangement according to claim44, wherein a sealant (67) is vulcanized on an inner side of the axiallyaligned section of the cylinder (5).
 46. The clutch arrangementaccording to claim 44, wherein the cylinder (5) is sealed relative tothe hub (3) by a separate sealant.
 47. The clutch arrangement accordingto claim 39, wherein the pressure compensation space (25) for a piston(10) is formed between a side axially pointing away from a pressurespace (6) of a piston-cylinder arrangement for the radially outer clutch(B) and a radially inner section (54) of the common disc carrier (9).48. The clutch arrangement according to claim 39, wherein in thepressure compensation space (25) for an actuating piston (10) for theouter clutch (B), a recoil element (26) is situated which directly orindirectly (34) supports itself axially by one of an end on theactuating piston (10) and by another end on a radially inner section(54) of the common disc carrier (9).
 49. The clutch arrangementaccording to claim 39, wherein in the pressure compensation space (25)for a piston (10), one radially aligned baffle plate (34) is fastened onan axially inner section (54) of a common disc carrier (9) in a mannersuch that between the two parts, one coolant or lubricant guide space(59) is formed for the coolant or lubricant flow (3) for the outerclutch (B).
 50. The clutch arrangement according to claim 39, wherein abaffle plate (34) has on a radially inner section, one inlet aperture(51) through which the coolant or lubricant can enter from the pressurecompensation space (25) for the outer clutch (B) into a coolant orlubricant guide space (59).
 51. The clutch arrangement according toclaim 39, wherein in an area of a radially outer section of a baffleplate (34) in a common disc carrier (9), one radially outlet aperture(48) is formed through which the coolant or lubricant can exit from acoolant or lubricant guide space (59).
 52. The clutch arrangementaccording to claim 39, wherein a flow duct (62) for the coolant orlubricant flow (30) is formed radially above an outlet aperture (48) ina common disc carrier (9) between the disc carrier (9) and a radiallyouter section of an actuating piston (17) for the radially inner clutch(E).
 53. The clutch arrangement according to claim 39, wherein in aparaxially aligned section (63) of a common disc carrier (9), radiallyaligned apertures (piercing 14) are formed through which the coolant orlubricant flow (30) can reach discs (21, 22) of the outer clutch (B).54. The clutch arrangement according to claim 39, wherein in diameterarea beneath a disc set for the radially inner clutch (E), two actuatingpistons (10, 17) are situated axially directly to right and left sidesnext to the common disc carrier (9).
 55. The clutch arrangementaccording to claim 39, wherein on an radially inner section a baffleplate (34) is pressed by a recoil element (26) situated in the pressurecompensation space (25) axially against a radially inner section (54) ofthe common disc carrier (9).
 56. The clutch arrangement according toclaim 39, wherein a baffle plate (34) is clamped on a radially outersection upon an inner side of a horizontally aligned section (47) of acommon disc carrier (9).
 57. The clutch arrangement according to claim39, wherein a baffle plate (34) carries on an inner side of a radiallyouter section a sealant (49) which seals the pressure compensation space(25) against an actuating piston (10) for actuating the outer clutch(B).
 58. The clutch arrangement according to claim 39, wherein thepressure space (8) of the piston-cylinder arrangement for actuation ofthe radially inner clutch (E) is essentially formed by a wall of theinner section (54) of a common disc carrier (9) that points away fromthe pressure compensation space (25) for a piston (10) of the outerclutch (B) and one section of a hub (3).
 59. The clutch arrangementaccording to claim 39, wherein for the inner clutch (E), one pressurecompensation space (31) is formed which is delimited by a hub (3), abaffle plate (19), the same as by a side of the actuating piston (17)pointing away from a common disc carrier (9).
 60. The clutch arrangementaccording to claim 39, wherein in a pressure compensation space (31) forthe actuating piston (17) of the inner clutch (E), one recoil element(18) is situated and supported axially by one end on a baffle plate (19)and by another end on the actuating piston (17).
 61. The clutcharrangement according to claim 39, wherein via a sealant (45), a baffleplate (19) seals the pressure compensation space (31) against aleft-side “t” leg (42) of a piston (17) pointing away from a common disccarrier (9).
 62. The clutch arrangement according to claim 39, whereinthe piston (17) for actuation of the inner clutch (E) is axially passedby a right-side “t” leg (43) to a paraxial section (47) of a common disccarrier (9).
 63. The clutch arrangement according to claim 39, whereinthe baffle plate (19) and the cylinder (5) are axially secured on thehub (3) by means of snap rings (4, 36).
 64. The clutch arrangementaccording to claim 39, wherein a hub (3) is situated upon an axialcontinuation (52) of a transmission housing (2), is rotatably supportedon a continuation (52) and axially supported via an axial bearing (53)against the continuation (52).
 65. The clutch arrangement according toclaim 39, wherein a transmission shaft (1) is designed as input shaft.66. The clutch arrangement according to claim 39, wherein upon a side ofthe baffle plate (19) remote from the pressure compensation space (31)for the actuating piston (17) of the inner clutch (E), an inner disccarrier (37) of the inner clutch (E) is situated and connected with atransmission shaft (39).
 67. The clutch arrangement according to claim39, wherein between an inner disc carrier (37) and a baffle plate (19)of the pressure compensation space (31) for the actuating piston (17) ofthe inner clutch (E), a flow route (64) is formed for receiving thelubricant and coolant flow (20) for the inner clutch (E).
 68. The clutcharrangement according to claim 39, wherein an outer disc carrier (38) ofthe radially outer clutch (B) is situated upon a side remote form a flowroute (64) of an inner disc carrier (37) of the inner clutch (E). 69.The clutch arrangement according to claim 39, wherein an outer disccarrier (38) of the radially outer clutch (B) is situated upon atransmission shaft (40) which by way of an axial bearing (56) is securedagainst a transmission shaft (39) on which an inner disc carrier (37) ofthe inner clutch (E) is fastened.
 70. The clutch arrangement accordingto claim 39, wherein a transmission shaft (39) carrying an inner disccarrier (37) of the inner clutch (E) is supported by means of an axialbearing (55) against a transmission shaft (1) carrying a hub (3) andagainst the hub (3).
 71. The clutch arrangement according to claim 39,wherein an actuating piston (10) of the outer clutch (B) has on aradially outermost end a paraxial section (65) which is designed as arotational speed indicator for a rotational speed sensor (12).
 72. Theclutch arrangement according to claim 39, wherein a radial arrangementof an aperture (51) in a baffle plate (34) defines a maximum fluid level(7) which the lubricant or coolant reaches in the pressure compensationspace (25) for the actuating piston (10) of the outer clutch (B). 73.The clutch arrangement according to claim 39, wherein a supply of thepressure compensation space (25) for a piston (10) of the outer clutch(B) and the supply thereof with coolant and lubricant are effected via ahole (57) in a hub (3) which communicates by flow technique with a hole(29) in the continuation (52) of the transmission housing (2).
 74. Theclutch arrangement according to claim 39, wherein a pressure space (6)for the piston-cylinder arrangement (3, 5, 10) for actuation of theouter clutch (B) is supplied with an actuating pressure via a hole (58)in a hub (3) which for its part is connected by flow technique with ahole or peripheral groove (27) in a continuation (52) of a transmissionhousing (2).
 75. The clutch arrangement according to claim 39, wherein apressure space (8) of the actuating cylinder for the radially innerclutch (E) is filled via hole (66) in a hub (3) which is in flowconnection with a separate hole or annular groove (28) in a continuation(52) of a transmission housing (2).
 76. The clutch arrangement accordingto claim 39, wherein the pressure compensation space (31) can besupplied with the lubricant or coolant via a hole (61) in a hub (3).